Ecology PPt Ch. 3

1. Biology Chapter 3
Mimi Zwaneveld
Kara Bradley
Alanah Nunez
Jessica Jewell

2. 3-1 : What is Ecology? (kara)
Interactions and interdependence
Ecology: is the scientific study of interactions among organisms and between
organisms and their environment, or surroundings.
Biosphere: the largest of nature's “houses”. It contains the combined portions of
the planet in which all of life exists, including land, water, and air, or
atmosphere.

3. Levels of Organization- To understand relationships within the biosphere, ecologists ask
questions about events and organisms that range in complexity from a single individual
to the entire biosphere.
Species: a group of organisms so similar to one another that they can breed and produce
fertile offspring
Populations: groups of individuals that belong to the same species and live in the same
area.
Communities: Assemblages of different populations that live together in a defined area.
Ecosystem: Is a collection of all the organisms that live in a particular place together
with their nonliving, or physical, environment.
Biome: A group of ecosystems that have the same climate and similar dominant
communities.

4. Ecological Methods
Observing- Often the first step in asking ecological questions. Some
observations are simple asking one question while some are more difficult that
have a first step leading to many more.
Experimenting- Experiments are used to test hypotheses. An ecologist often
sets up an artificial experiment to imitate something that happens in the
natural world.
Modeling- Ecologists make models to gain insight to a complex phenomena.
These models usually consist of mathematical formulas based on data collected
through observations and experiments.

5. 3-2 : Energy Flow (Mimi)
Autotroph- an organism that can make its own food and produce complex organic compounds from simple
substances present in its surroundings, generally using energy from light or inorganic chemical reactions.
Producers- organisms that make their own food; they are also known as autotrophs. They get energy from chemicals
or the sun, and with the help of water, convert that energy into useable energy in the form of sugar, or food. The most
common example of a producer are plants.
Photosynthesis- a process used by plants and other organisms to convert light energy, normally from the Sun, into
chemical energy that can be later released to fuel the organisms' activities
Chemosynthesis- the biological conversion of one or more carbon molecules (usually carbon dioxide or methane) and
nutrients into organic matter using the oxidation of inorganic compounds (e.g. hydrogen gas, hydrogen sulfide) or
methane as a source of energy, rather than sunlight
Heterotrophs- an organism requiring organic compounds for its principalsource of food.
Consumers- an organism, usually an animal, that feeds on plants or otheranimals.
Herbivores- an animal that feeds on plants.

6. 3-2 : Energy Flow continued
Carnivores- an organism that eats meat or flesh.
Omnivores- an organism that eats both plants and
animals.
Decomposers- an organism, especially a soil bacterium,
fungus, or invertebrate, that decomposes organic material.

7. Pictures

8. 3-2: Food Chains (Jessica)
Food chain- a series of steps in which organisms transfer energy by eating or being eaten
Food web- network of complex interactions formed by the feeding relationships among the
various organisms in an ecosystem
Trophic level- step in a food chain or food web
Ecological pyramid- diagram that shows the relative amounts of energy or matter within each
trophic level in a food chain or food web
Biomass- total amount of living tissue within a given trophic level
Biogeochemical cycle- process in which elements, chemical compounds, and other forms of
matter are passed from one organism to another and from one part of the biosphere to
another
Evaporation- process by which water changes from a liquid into an atmospheric gas
Transpiration- loss of water from a plant through it leaves
Food web

9. 3-2: Food Chains (continued)
Nutrient- chemical substance that an organism requires to live
Nitrogen fixation- process of converting nitrogen gas into ammonia
Denitrification- conversion of nitrates into nitrogen gas
Primary productivity- rate at which organic matter is created by producers in an ecosystem
Limiting nutrient- single nutrient that either is scarce or cycles very slowly, limiting the growth
of organisms in an ecosystem
Algal bloom- an immediate increase in the amount of algae and other producers that results
from a large input of a limiting nutrient
Algal bloom

10. 3-3 : (Alanah)
Alanah is not in this class anymore :(